What are Claude Code hooks?

Hooks are event-driven automation scripts that execute in response to Claude Code events, allowing you to validate operations, add context, and integrate external tools.

How do I persist environment variables across a session?

You can use a SessionStart hook to append export commands to the $CLAUDE_ENV_FILE, which ensures those variables are available to Claude for the duration of the session.

What is the benefit of a Prompt-Based hook?

Prompt-based hooks use LLM reasoning to make context-aware decisions based on natural language, which is often more flexible than rigid bash scripts for complex validation.

Can I modify tool inputs using hooks?

Yes, PreToolUse hooks can intercept tool calls and return an 'updatedInput' to modify the parameters before the tool actually executes.

What is an Async hook used for?

Async hooks run in the background without blocking Claude's response, making them perfect for fire-and-forget tasks like logging metrics or sending Slack notifications.

Hook Development for Claude Code

Name: Hook Development for Claude Code
Author: astrosteveo

byastrosteveo

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Developer Tools

Streamlines the creation of event-driven automation hooks to validate tool use, enforce policies, and manage project context within Claude Code.

About

The hook-development skill provides a comprehensive framework for implementing sophisticated automation within the Claude Code environment. It guides developers through the creation of various hook types—including prompt-based, command, agent, and asynchronous hooks—to respond to lifecycle events such as tool execution, session starts, and task completion. By leveraging these hooks, developers can build robust guardrails that block dangerous commands, automate environment setup via session variables, and perform multi-turn architectural analysis, ultimately creating a more secure and efficient AI-assisted development workflow.

Key Features

Prompt-based hooks for LLM-driven, context-aware validation logic
1 GitHub stars
Deterministic command hooks for bash-based file and system operations
Comprehensive event support including PreToolUse, SessionStart, and Stop
Multi-turn Agent hooks for deep code analysis and complex validation
Asynchronous execution for non-blocking logging and telemetry

Use Cases

Automatically loading project-specific context and environment variables at session start
Enforcing code quality and architectural standards through automated review hooks
Blocking dangerous or unauthorized shell commands before execution

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add astrosteveo/marketplace hook-development

For use in Claude.ai and ChatGPT

Download Skill

GitHub